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Studies of elemental abundances in stars belonging to the thin and the thick disk of our Galaxy are reviewed. Edvardsson et al. (1993) found strong evidence of [alpha/Fe] variations among F and G main sequence stars with the same [Fe/H] and…

Astrophysics · Physics 2007-05-23 Poul E. Nissen

Theories of thick disk formation can be differentiated by measurements of stellar elemental abundances. We have undertaken a study of metal-poor stars selected from the RAVE spectroscopic survey of bright stars to establish whether or not…

We trace the evolution of eight edge-on star-forming disk galaxies by analyzing stellar population properties of their thin and thick disks. These galaxies have relatively low stellar masses (4~$\times$~10$^9$ to…

Recent observations demonstrate that the thin and thick disks of the Galaxy have different chemical abundance trends and evolution timescales. The relative abundances of $\alpha$-elements in the thick Galactic disk are increased relative to…

Astrophysics · Physics 2009-11-11 T. V. Nykytyuk , T. V. Mishenina

We highlight some results from our detailed abundance analysis study of 703 kinematically selected F and G dwarf stars in the solar neighbourhood. The analysis is based on spectra of high-resolution (R=45000 to 110000) and high…

Astrophysics of Galaxies · Physics 2015-05-30 T. Bensby , S. Feltzing

We analyze high quality abundances data of solar neighborhood stars and show that there are two distinct regimes of [alpha/Fe] versus age which we identify as the epochs of the thick and thin disk formation. A tight correlation between…

Astrophysics of Galaxies · Physics 2015-06-16 M. Haywood , P. Di Matteo , M. Lehnert , D. Katz , A. Gomez

We have investigated the abundance of several chemical elements in two large stellar samples kinematically representative of the thin and the thick disks of the Galaxy. Chemical, kinematical and age data have been collected from high…

Astrophysics · Physics 2007-05-23 Pascal Girard , Caroline Soubiran

[ABRIDGED] In order to trace the origin and evolution of carbon in the Galactic disk we have determined carbon abundances in 51 nearby F and G dwarf stars. The sample is divided into two kinematically distinct subsamples with 35 and 16…

Astrophysics · Physics 2009-11-11 T. Bensby , S. Feltzing

We performed an uniform spectroscopic analysis of 1111 FGK dwarfs observed as part of the HARPS GTO planet search program. We applied a purely chemical approach, based on [alpha/Fe] ratio, to distinguish the various stellar components in…

Earth and Planetary Astrophysics · Physics 2013-07-09 V. Zh. Adibekyan , N. C. Santos , S. G. Sousa , G. Israelian , P. Figueira

[Abridged abstract] We have performed an abundance analysis for 176 F- and G- dwarfs of the Galactic thick disk component. Using accurate radial velocities combined with $Hipparcos$ astrometry, kinematics (U, V, and W) and Galactic orbital…

Astrophysics · Physics 2009-11-13 Bacham E. Reddy , David L. Lambert , Carlos Allende Prieto

The abundances of iron and oxygen are homogeneously determined in a sample of 523 nearby (d<150 pc) FGK disk and halo stars with metallicities in the range -1.5<[Fe/H]<0.5. The oxygen abundances were inferred from a restricted non-LTE…

Astrophysics · Physics 2009-11-13 I. Ramirez , C. Allende Prieto , D. L. Lambert

We have studied 23 long-lived G dwarfs that belong to the thin disk and thick disk stellar populations. Abundances have been derived for 24 elements: O, Na, Mg, Al, Si, Ca, Ti, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd,…

Astrophysics · Physics 2008-11-26 Mary-Margaret Brewer , Bruce W. Carney

... We confirm the well-established differences for [$\alpha$/Fe] at a given metallicity between the local thin and thick disks. For all the elements investigated, we find no chemical distinction between the bulge and the local thick disk,…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. Alves-Brito , J. Melendez , M. Asplund , I. Ramirez , D. Yong

A linear [Fe/H]-[O/H] relation is found for different stellar populations in the Galaxy (halo, thick disk, thin disk) from a data sample obtained in a recent investigation (Ram{\'\i}rez et al. 2013). These correlations support previous…

Astrophysics of Galaxies · Physics 2017-06-15 R. Caimmi

We present first results from a program to measure the chemical abundances of a large (N>30) sample of thick disk stars with the principal goal of investigating the formation history of the Galactic thick disk. Our analysis confirms…

We explore the structure of the element abundance--age--orbit distribution of the stars in the Milky Way's low-$\alpha$ disk, by (re-)deriving precise [Fe/H], [X/Fe] and ages, along with orbits, for red clump stars from the APOGEE survey.…

Solar and Stellar Astrophysics · Physics 2019-10-09 Melissa K. Ness , Kathryn V. Johnston , Kirsten Blancato , Hans-Walter Rix , Angus Beane , Jonathan C. Bird , Keith Hawkins

The space velocities and Galactic orbital elements of stars calculated from the currently available high-accuracy observations in our summary catalog of spectroscopic magnesium abundances in dwarfs and subgiants in the solar neighborhood…

Astrophysics · Physics 2015-06-24 V. A. Marsakov , T. V. Borkova

The behavior of the relative magnesium abundances in the thin-disk stars versus their orbital radii suggests that the star formation rate in the thin disk decreases with increasing Galactocentric distance, and there was no star formation…

Astrophysics · Physics 2007-10-29 V. A. Marsakov , M. V. Shapovalov , T. V. Borkova

This paper focuses on carbon that is one of the most abundant elements in the Universe and is of high importance in the field of nucleosynthesis and galactic and stellar evolution. Even nowadays, the origin of carbon and the relative…

Ever since a thick disk was proposed to explain the vertical distribution of the Milky Way disk stars, its origin has been a recurrent question. We aim to answer this question by inspecting 19 disk galaxies with stellar mass greater than…

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